Shooting way past the subsonic boundary is a very complex task that will only happen when the weapon is capable of outstanding accuracy and the sniper is a superb wind reader
Most readers will be aware of recent sniper record shots. Some will have researched the awesome snipers who made them and the equipment they used. An even smaller group of these people will have gone to their logbooks and computers to try to find out if these shots can be made—particularly the pair of 2,707-yard kill shots delivered in November 2009 by British Cpl. Craig Harrison against Taliban insurgents in Afghanistan.
My good friend and fellow ballistics freak Louis Corkern from CC International and I both wanted to know, so we went to the field to test it. We opted to shoot .338 Lapua Magnum rifles, too, like Cpl. Harrison—he shot the 300-grain Scenars and I shot the 250-grain Scenar, which is more standard among the UK and NATO military. Personally, this decision was based on my previous unsuccessful attempts to shoot this far with a .50 BMG and MK-211 ammunition, whose ballistics needed more elevation than any available scope could supply. One thing to keep in mind, you can’t hit what you can’t see. If the target is below and out of the scope’s view after you stack all of the methods of adding elevation, the probability of hitting the target is about as good as the target being struck by lightning.
Louis wanted to use his Desert Tactical Arms (DTA) .338 LM with a 1:9 twist barrel perfectly suited to the 300-grain bullets. I opted for my McRee Stiller TAC338 rifle with a 1:9, 35 Pac-Nor barrel. Both rifles wear long 27-inch barrels, since we believe in long barrels as opposed to the current trend of HTI (Hard Target Interdiction) calibers with short barrels. I want speed for extreme long-range ballistics, and I need barrel length to extract it from the powder. The velocity lost with shorter barrels may seem irrelevant to some, but for extreme sniping we want every foot per second (fps) available. Terminal ballistic performance and ease of transport does not justify the larger caliber’s extra weight and cost. And at under 800 meters, good .308 API rounds like the RUAG 196-grain FMJHC exhibit very similar performance to short-barrel .338 LM rifles with “slowed” API rounds.
Shooting way past the subsonic boundary is a very complex task that will only happen…
by Jon Sundra / Mar 17, 2013